The prior art includes many systems for achieving interactive communication between a central station and geographically disbursed TV users. For example, in my previous patent U.S. Pat. No. 5,257,099, issued Oct. 26, 1993, a typical satellite communication system employing intermediate repeater stations is disclosed.
In my earlier system, a network of local audience response systems, where TV watchers are located, is coupled together with a central audience response processing station via a satellite communication link. The system required the embedding of questions, destined for the TV audience, in the TV picture program transmission. This real time system required that each local area repeater station and each end user response unit be identified and verified by allocation of specific time slots for responses from a TV watcher synchronized to a TV picture program transmission carrying the audience questions to be answered. Response units in the audience generate answers in the form of "beep" signals that are communicated back to a central station, via a repeater station, and the answer is synchronized with the question destined for a particular response unit so that positive identification of the particular response unit may be made in real time.
Several significant shortcomings existed in my prior patents. For example, the central station usually required a studio for generating a TV program with questions that were embedded in the video signal during specific time slots of the synchronization interval of each horizontal line in the video signal, which also contained the normal TV program.
In utilizing my previous system, a TV viewer would watch a program transmitted from the central station and when prompted to answer a question, the viewer would do so with an infrared remote device. His response is synchronized with the transmission of the question to his particular TV so that the central station could identify the answer from a particular response unit. This previous system is quite limiting in that the viewer can only interact with the system for a particular transmitted TV program, in real time. The prior system is also quite expensive in that it incorporates two-way communication over an independent channel from a central location to local area repeaters and then to viewers at response units.